v.1. I. Introduction. II. Outline of the electromagnetic connections. Appendix A: The rotational ether in its application to electromagnetism. III. The elements of vectorial algebra and analysis. IV. Theory of plane electromagnetic waves. Appendix B: A gravitational and electromagnetic analogy.--v.2. V. Mathematics and the age of the earth. VI. Pure diffusion of electric displacement. Appendix C: Rational units. VII. Electromagnetic waves and generalised differentiation. VIII. Generalised differentiation and divergent series. Appendices: D. On compressional electric or magnetic waves. E. Dispersion. F. On the transformation of optical wave surfaces by homogeneous strain. G. Note of the motion of a charged body at a speed equal to or greater than that of light. H.Note on electrical waves in sea water. I. Note on the attenuation of Hertzian waves along wires.-v.3. IX. Waves from moving sources. Appendix J: Note on the size and inertia of electrons. Appendix K. Vector analysis. X. Waves in the ether